2.0-disable-pool-member

Exercise 2.0 - Disabling a pool member

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Table of Contents

• Objective
• Guide
• Playbook Output
• Solution

Objective

For this last exercise instead of prescriptive step-by-step walkthrough a framework of objectives with hints for each step will be provided.

Demonstrate the removal of a node from the pool. Build a Playbook that:

• Retrieve Facts from BIG-IP for the pools present on the BIG-IP (in our example only one pool is present)
• Display pools available
• Store the pool name as a fact
• Display all the pool members that belong to the pool => IP and port information to the terminal window
• Prompt the user to disable a particular member or disable all members of the pool
• Force the appropriate pool members offline

Guide

Step 1:

Using your text editor of choice create a new file called disable-pool-member.yml.

[student1@ansible ~]$ nano disable-pool-member.yml

vim and nano are available on the control node, as well as Visual Studio and Atom via RDP

Step 2:

Enter the following play definition into disable-pool-member.yml:

---

- name:  Disabling a pool member
  hosts: f5
  connection: local
  gather_facts: false

Step 3

Add a tasks section and then set a fact for the provider. Once you set the provider you can re-use this key in future tasks instead of giving the server/user/password/server_port and validate_certs info to each task.

---
- name: "Disabling a pool member"
  hosts: lb
  gather_facts: false
  connection: local

  tasks:
  - name: Setup provider
    set_fact:
     provider:
      server: "{{private_ip}}"
      user: "{{ansible_user}}"
      password: "{{ansible_ssh_pass}}"
      server_port: "8443"
      validate_certs: "no"

Now in the next task you can use provider as follows:

bigip_device_info:
  provider: "{{provider}}"
  gather_subset:
  - ltm-pools

You DO NOT need to pass the server_ip/user/password etc. for each module going forward

---
- name: "Disabling a pool member"
  hosts: lb
  gather_facts: false
  connection: local

Next, add a task for the objective listed below:

• Retrieve Facts from BIG-IP for the subset ltm-pools

HINT: Try using the bigip_device_info module from Exercise 1.1

Step 5

Next, add a task for the objective listed below:

• Display the pool information to the terminal window

HINT: Find a way to loop on the output from the above step. Remember to also use the debug module

Step 6

Next, add a task for the objective listed below:

• Store the pool name as a fact

HINT: An easy way to set fact variables within a Playbook dynamically is using the set_fact module

Step 7

Next, add a task for the objective listed below:

• Display members belonging to the pool

HINT: Remember to use the debug and refer Exercise 1.4

Step 8

Next, add a task for the objective listed below:

• Prompt the user to enter a Host:Port to disable a particular member or 'all' to disable all members

HINT: Use the prompts module

Step 9

Next, add a task for the objective listed below:

• Read the prompt information and disable all members or a single member based on the input from the user

HINT: Remember to use when conditions and loops and BIG-IP pool member module

Step 10

Run the playbook - exit back into the command line of the control host and execute the following:

[student1@ansible ~]$ ansible-playbook disable-pool-member.yml

Playbook Output

The output will look as follows.

[student1@ansible ~]$ ansible-playbook disable-pool-member.yml

PLAY [Disabling a pool member] ******************************************************************************************************************************

TASK [Setup provider] *******************************************************************************************************************************
ok: [f5]

TASK [Query BIG-IP facts] ***********************************************************************************************************************************
changed: [f5]

TASK [Display Pools available] ******************************************************************************************************************************
ok: [f5] => (item=http_pool) => {
    "msg": "http_pool"
}

TASK [Store pool name in a variable] ************************************************************************************************************************
ok: [f5] => (item=None)
ok: [f5]

TASK [Show members belonging to pool http_pool] *************************************************************************************************************
ok: [f5] => (item=host1:80) => {
    "msg": "host1:80"
}
ok: [f5] => (item=host2:80) => {
    "msg": "host2:80"
}

TASK [pause] ************************************************************************************************************
[pause]
To disable a particular member enter member with format member_name:port
To disable all members of the pool enter 'all':
host1:80

TASK [Disable ALL pool members] ************************************************************************************************************************
skipping: [f5] => (item=host1:80)
skipping: [f5] => (item=host2:80)

TASK [Disable pool member host1:80] *************************************************************************************************************************
changed: [f5]

PLAY RECAP **************************************************************************************************************
f5                         : ok=7    changed=2    unreachable=0    failed=0

Solution

The solution will be provided by the instructor if you are stuck. The GUI should show something similar to the following with a black diamond indicating the specified node was forced offline.

-- You have finished this exercise. Click here to return to the lab guide